FTree.select throws IndexError: list index out of range

[arsamigullin]

Hello.
Looks like there is a bug in the select function

cpbook-code/ch2/ourown/fenwicktree_ds.py

Line 36 in fa53432

if k > self.ft[i + p]:

Steps to reproduce:

ft = FTree([1,2,3,4,5])
ft.select(15) # this throws IndexError: list index out of range in line 36

Expected behavior:
According to CP4 book, the select function "finds the smallest index/key i so that the cumulative frequency in the range [1..i]>=k". So the function should return 6 because the smallest index (of FTree.ft array) where the cumulative frequency is at least 15 is 6

[rchavesf]

@arsamigullin The answer for your example should be 5. However, the issue exists and it can be solved by #86.